Automatic gas-feed for vacuum-tubes.



PATENTED JUNE 11, 1907.

D. MOP. MOORE. AUTOMATIG GAS FEED FOR VACUUM TUBES.

APPLICATION FILED MAY 8, 1906.

INVENTOR Dan/e /]77 J ;r/a 71 M re W/T N 8858:

ATTORNEYS.

' ally 4 UNITED STATESWPATENT OFFICE.

DANIEL MOFARLAN MOORE, OF NEWARK, NEW JERSEY, ASSIGNOR TO MOORE ELECTRICAL 00., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented June 11, 1907.

Application filed May 8, 1906- Serial No. 315,730.

To aZZ whom it may concern:

Ea: Be it known that I, DANIEL McFARLAN MOORE, a citizen of the Umted States, and a resident of Newark, in the county of Essex and State of New Jersey, (with post-ofiice address 52 Lawrence street,) have invented certain new and useful Improvements in Automatic Gas-Feeds for Vacuum-Tubes, of

which the following is a specification.

My present invention relates to that class of; devices termed vacuum tubes and which are supplied with electrodes or terminals for causing electric energy to pass through the contained gas or vapor.

The invention is particularly useful for vacuum tube or vapor electric lamps, but may also be ap lied to vacuum or vapor rectifiers, X-ray tu es, wireless telegraph apparatus or other devices which employ a vacuum through which the electric energy passes.

The object of my invention is to prevent changes in the degree of vacuum due to the passage of the electric energy and consists in animproved means for automatically supplying the gas or vapor to the vacuous spaces so as to maintain t e desired gas or vapor tension.

The invention consists essentially in the combination of a vacuum tube, a thermostat heated by current varying in amount with the resistance of the gas in the tube, and means controlled by said thermostat for supplying gas. to the tube in rcgulatedamounts so as to maintainthe gas tension or density therein at substantially normal degree.

The invention consists further in the combination with a vacuum tube, of an electricheated thermostat connected to the circult of the tube, and means controlled in theiraction by said thermostat for supplying gas to the tube.

cal section of an apparatus embodying my invention. Figs. 2 and 3 illustrate modifications. Fig. 4 is a modification of the circuits.

For the purposes of illustration only, I will describe the invention as applied to a vacuum tube lamp in which the gas tension or density is to be maintained at. such a degree that a decrease of the density will have the efiect of lowering the resistance of the gas to the passage of an electric current.

1 indicates the vacuum tube and 2 the usual internal electrodes, by means of which electrical energy of any desired form or character may be made to pass through the contained gas or vapor.

3 is a tube or pipe through which gas may be fed into the tube to bring the tension thereof back to normal when it shall have decreased owin to the action of the electrical current fowing in the tube. If the gas is supplied to the tube through the operation of a valve or similar gas feed controlling the flow from a body of gas of a tension greater than that in the tube, I prefer to employ the form of valve described in my prior application for patent filed Aug. 21st, 1905 and in a division thereof filed April 16th, 1906, but might employ any other constructi on of valve sufficiently delicate and certain in its action.

4 indicates a valve chamber containing a gas of a density-or tension greater than that in tube 1 and supplied with gas from any source. Such source may be the atmosphere fed through a chemical for removing its oxygen as described and claimed in my application for patent filed April 2nd, 1906, S. N. 309,286 or may be a gas generator as described and claimed in my application for patent filed April 16th, 1906, S. N. 311,815 or a tank charged with the desired gas as described and claimed in my application for patent filed April 2nd, 1906, S. N. 309,288 or mav be any other source.

Interposed in the passage between the porous material like porous electric light carbon and is adapted, when exposed to the gas in chamber 4, to allow gas to percolate or flow through its pores in minute amount to the feed tube or pipe 3. Any means may be used for adjusting the level. of the mercury, as for instance, an adjustable'plunger or liquid displacer 7. Variations in the height of the liquid 6 are brought about through the v at the valve.

action of a thermostat heated by current flowing in a circuit formed in part of the gas I tube or chamber in which mercury 6 is located is preferably large so that the effects of contraction or expansion, due to change of heating effect of coil 10, will be -multiplied Heating coil 10 is connected, in Fig. 1, in shunt to the main circuit through the tube. Normally, and when the gas tension and hence resistance of the circuit throu h the tube are normal, sufficient current will e forced to flow through the heating coil of the thermostat to maintain the level of the liquid 6 at a point where no or but little gas can leak into the feed tube 3. If, however, the resistance of the gas in tube 1 decreases, owing to decreases of the gas tension, less current will flow in the heating coil of the thermostat and the thermostat will contract so that the valve will be opened or more fully opened by a change in the level of its liquid and thus allow gas to flow to the tube 1 until the gas tension or density in said tube is restored to normal. the coils of the thermostat and the flow of gas to the tube will be shut down or cut off.

Fig. 2 shows a modification wherein the thermostat is in the direct circuit with electrodes 2 of the tube and operates to change the level of liquid in the valve by operating on a liquid displacer or plunger 7. In this figure, 12 indicates an expansible rod of any suitable material included in the circuit of the electrodes 2 and heated by the currentflowing through the same. The rod 12 is sustamed from a support 13 and its action may be assisted by a spring 14.. The plunger 7 is connected to the lower or free end of rod 12 by a lever 15. When the gastension or density in the tube 1.decreases, more current flows in the rod 12 and by heating the same causes it to expand thus raising plunger 7 and allowing the level of the liquid 6 to fall so as to feed more gas to the tube 1. The

More current will then fiow through restoration of the density or tension of the gas in tube 1 brings about a decreased flow of current in the rod 12, which thereupon contracts and shuts or partially shuts the valve. v

Obviously, the thermostat might be connected in other ways to the circuit. Thus for instance, as shown in Fig. 4, it might be in the primary of a potential raising converter whose secondary supplies the tube, The mains to which the converter is connected being constant potential mains, the thermostat would act in the manner described in connection with Fig. 2 and would vary in its effect With" the variation in the electrical resistance of the gas within the tube due to change of gas tension or density.

In the modification shown in Fig. 3, the thermostat controls the action of a valve not by direct mechanical connection, butfithrough an electrical device comprising an electromagnet, the coils of which are indicated at 16., The movable core of said magnet is connected to the plunger or displacer 7 and the circuit of said magnet is closed and opened by changes in the condition of the thermo- 9 stat. In the case of a mercury thermostat, the circuit may be closed and opened through changes of height of the column of mercury of the thermostat, said column forming a part of the circuit of thecoil 16 and any suitable source of electric energy 17.

The operation of the devicewhich will be readily understood from the previous description is briefly: When the gas tension in tube 1 decreases, more current flows throughiroov the coils of the thermostat, its mercury column rises and closes the circuit of the coils 16 and the core of the latter operates upon the valve so as to open or more fully open the same and feed gas to the tube to restore the IO 5 gas tension or density therein.

What I claim as my invention is 1.. The combination of a vacuum tube, a thermostat heated by current varying in amountwith the resistance of the gas in the 1 1o tube, and means controlled by said thermostat for supplying gas to the tube in regulated amounts so as to maintain the gas tension or density therein at substantially normal degree.

2. The combination with a vacuum tube, of an electrically heated thermostat connected to the circuit of the tube, and mears controlled in their action by said thermostat for sup lying gas to the tube.

3. T e combination of a vacuum tube, a valve for admitting gas to the tube, and a thermostat controlling the action of said valve and heated .by a current taken from the current supply for said tube and varying in 12 5 amount wit the resistance of the gas within the tube.

4c. The combination of a vacuum tube, a valve havin a li uid by whose changes of height the ow or gas to the tube is con- 0 sea-tee trolled, and a thermostat controlling the ac-- tion of a valve and heated by a current varying in amount with the resistance of the gas in the tube.

5. The combination of a vacuum tube, aniereury thermostat heated by current vary ing in amount with the resistance of the gas and a gas assage opened and closed by variations in t e level of the mercur of the thermostat and controlling in turn the passage of a gas to the tube.

6. The combination of a vacuum tube lamp, a Valve consisting substantially of a mass of porous material'and a sealing liquid, a thermostat responsive to Variations in the resistance of the gas in the tube, and means controlled by said thermostat for yaryin the height of the liquid and thereby contro lling the flow of gas to the tube.

Signed at New York-in the county of New York and State of New York this 5th day of May A. D. 1906.

' DANIEL MOFARLAN MOORE.

Witnesses:

C. F. TISCHNER, Jr., LILLIAN BLoND. 

